Tag Archive: potable water contaminants


All water tanks accumulate sediment over time.  The soft sediment in the floor of water tanks and towers becomes a safe habitat for bacteria, protozoa and even VIRUSES!   *** see reference at bottom of the page.

Out of sight out of mind-

No one thinks about the sediment.   Most have no idea it is even there.

Not the water utility administrators, not the mayor not the elected city council members.  Many times elected officials vote to clean or  repaint the exterior of a water tower and never consider the inside condition.  The popular view is that Pure Treated drinking water is pumped into the water storage tank or tower where it is held, until the end user opens a tap at their kitchen sink and gets a glass of crystal clean water.

The Truth-

All water distribution systems accumulate sediment in tanks over time.

The water is often tested daily, if the chlorine residual goes down – operators do not ask why, they just add more chlorine, over time the additional chlorine breaks down and itself becomes a contaminate in the tank that can cause cancer.   *** See References below

Instead of constantly adding more and more treatment chemicals, simply cleaning the sediment from the floor of the tanks is the solution.

A countless number of biological contaminates can use the sediment in the floor of water tanks and towers to get a foot hold in a municipal drinking water system and grow into a real health concern.  Why should we care what is on the bottom of a water storage tank?

We drink off the bottom of water storage tanks!  Of course like many things the adverse health effects are unequally distributed to poor communities where drinking store bought bottled water is not a given, It is also these communities who have underfunded water systems that suffer from lack of maintenance.

Many utility systems that can afford inspection and cleaning of their systems simply do not allocate the funds for it because there are no regulations requiring them to do so.

In Texas yearly inspections of water storage tanks and towers are required.

Tanks get inspected in Texas.  The problem in this state is there is no rule or regulation requiring tanks to be cleaned. So while thanks get inspected every year,  most are seldom if  ever cleaned.

The AWWA (American Water Works Association)  recommends that water storage tanks be cleaned every 3 to 5 years or as needed.  The EPA has published multiple white papers about contamination public water systems and the importance to keep tanks free of sediment.

Few ever read EPA white papers and AWWA recommendations are largely ignored when there are no rules or regulations backing them up.

Of course there is always someone who is doing the right thing out there, just because it is the right thing to do.  In this case that would be the City of Arlington, Texas.

According to surveys conducted by the Environmental Working Group, Arlington, Texas has The best water in the United States, probably making it the best water in the world.  Arlington is located in the middle of the DFW metroplex getting its water from the same source as 50 other systems.   The water is treated in two water plants using similar treatment chemicals and methods as surrounding systems.

What sets them apart?  For the past 18 years But they  have made a commitment to keep their tanks clean,  Every year a Potable Water Dive crew is contracted to vacuum the tanks clean while they remain full of treated drinking water.    The divers literarily clean dust from the floor of water storage tanks, while surrounding cities allow multiple inches to accumulate before cleaning.

Too many water utilities in this country have no idea how much sediment if  any  is in the floor of their water storage tanks because they have never hired an inspection crew with underwater cameras to check it out.  It is never thought of so they stay caught in the cycle of adding more and more treatment chemicals when contamination is detected.

Lack of regulations in this overlooked undervalued part of our infrastructure is needlessly putting millions of people at risk for illness, cancer and even death.  When the solution is as simple as cleaning the floor of a storage area.  It just so happens that this area stores water, and it is often 150 foot or more up in the air.

The City of Arlington has proven the effectiveness of keeping water storage tanks clean,

According to the research I did for my book “Inspecting and Cleaning Potable Water Storage”  the majority of states do not have regulations requiring inspection or cleaning.

Do you think the EPA should require tanks to be Cleaned?

Take the poll :     CLICK HERE AND TAKE THE POLL AT THE BOTTOM OF THIS BLOG

Please share this with friends check out my Videos posted on you tube:

RPCWTP (Ron Perrin Clean Water Tank Project) VIDEO https://youtu.be/RrngivTqdIs

100_0135

https://youtu.be/RrngivTqdIs

Out of sight out of Mind on Facebook 

https://www.facebook.com/cleanwatertankproject/ 

This is a vastly complicated subject, that can be pulled down to three very simple terms.

  1. If you have a water storage tank or tower in your town there is sediment in it.
  2. Sediment bad,
  3. Remove Sediment and you remove the inorganic contaminates the habitat that organic contaminates can grow in.

See:  Disinfection byproducts list at: http://water.epa.gov/drink/contaminants/index.cfm#Byproduc

Reference: Health Risk From Microbiological Growth and Biofilms in Drinking water Systems.  Published by  the EPA office of Water  June 17, 2002.

http://www.epa.gov/ogwdw/disinfection/tcr/pdfs/whitepaper_tcr_biofilms.pdf

QUOTE:

PAGE 26        G. Sediment Accumulation

Significant microbial activity may occur in accumulated sediment (USEPA, 1992b). Organic and inorganic sediments can also accumulate in low-flow areas of the distribution system, and enhance microbial activity by providing protection and nutrients (USEPA, 1992b). Biofilms that slough can accumulate in the periphery of distribution systems leading to sediment accumulation and the proliferation of some microorganisms (van der Kooij, 2000). Sediments may be an important source of nutrients in open finished water reservoirs, by accumulating slowly biodegrading materials which

are then broken down and released into the water column (LeChevallier, 1999b). The opportunities for biofilm development may be more abundant in storage tanks than in distribution system piping. Frequently, water is drawn from storage tanks only when water demand is high, such as during drought, fire flow, and flushing operations. This intermittent use results in prolonged storage times that may lead to increased sediment accumulation and lack of a disinfectant residual in the finished water storage vessel. Biological and aesthetic effects can be observed following the release of accumulated sediments from low flow areas of the distribution system (Geldreich, 1990).

Many studies have identified microbes in accumulated sediments, including both pathogens and non-pathogens. These include bacteria, viruses, protozoa, algae, fungi and invertebrates. Opportunistic pathogens that have been detected, and can multiply in sediments, include Legionella and mycobacteria (van der Kooij, 2000). Some primary pathogens can also survive for some time in sediments. Hepatitis A virus survived more than four months in sediments at both 5/C and 25/C (Sobsey et al., 1986). Other opportunistic pathogens found in sediments include Pseudomonas fluorescens

and Flavobacterium spp. (Berger et al., 1993). Sediments can also release nutrients into the water which stimulate biofilm growth downstream (LeChevallier, 1999b).

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Page 34      I. Proper Storage Vessel Management and Alteration

Proper storage vessel management and alteration, when necessary, can prevent contamination of the distribution system. Following TCR violations in 1996 in Washington D.C., one measure that proved effective in bringing the system back into compliance was the cleaning, inspection and disinfection of storage tanks and reservoirs (Clark, et al., 1999).

END QUOTE

A list of possible Drinking Water Contaminants has been posted by the EPA

The link below gets you top the EPA page that has National Primary Drinking Water Regulations (NPDWRs or primary standards) are legally enforceable standards that apply to public water systems. Primary standards protect public health by limiting the levels of contaminants in drinking water. Visit the list of regulated contaminants with links for more details.

http://www.epa.gov/safewater/contaminants/index.html#micro

The problem with the EPA web site it that it is constantly in motion with thousands of web pages and hundreds being added daily.  I have elected to repost the list of list of regulated contaminants here to make it easier to find when people search the web.  The EPA posted this list in June of 2003 with this identifier #. EPA 816-F-03-016.  I have personally found this information to be very hard to find when searching their site. In addition to that you never know when it will be taken down.  All the more reason to re-post it here where more people will be able to find it when searching for Drinking Water Contaminates.

Microorganisms
Contaminant MCLG1
(mg/L)2
MCL or TT1
(mg/L)2
Potential Health Effects from Ingestion of Water Sources of Contaminant in Drinking Water
Cryptosporidium (pdf file)
zero
TT 3
Gastrointestinal illness (e.g., diarrhea, vomiting, cramps) Human and animal fecal waste
Giardia lamblia
zero
TT3
Gastrointestinal illness (e.g., diarrhea, vomiting, cramps) Human and animal fecal waste
Heterotrophic plate count
n/a
TT3
HPC has no health effects; it is an analytic method used to measure the variety of bacteria that are common in water. The lower the concentration of bacteria in drinking water, the better maintained the water system is. HPC measures a range of bacteria that are naturally present in the environment
Legionella
zero
TT3
Legionnaire’s Disease, a type of pneumonia Found naturally in water; multiplies in heating systems
Total Coliforms (including fecal coliform and E. Coli)
zero
5.0%4
Not a health threat in itself; it is used to indicate whether other potentially harmful bacteria may be present5 Coliforms are naturally present in the environment; as well as feces; fecal coliforms and E. coli only come from human and animal fecal waste.
Turbidity
n/a
TT3
Turbidity is a measure of the cloudiness of water. It is used to indicate water quality and filtration effectiveness (e.g., whether disease-causing organisms are present). Higher turbidity levels are often associated with higher levels of disease-causing microorganisms such as viruses, parasites and some bacteria. These organisms can cause symptoms such as nausea, cramps, diarrhea, and associated headaches. Soil runoff
Viruses (enteric)
zero
TT3
Gastrointestinal illness (e.g., diarrhea, vomiting, cramps) Human and animal fecal waste

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Disinfection Byproducts
Contaminant MCLG1
(mg/L)2
MCL or TT1
(mg/L)2
Potential Health Effects from Ingestion of Water Sources of Contaminant in Drinking Water
Bromate
zero
0.010
Increased risk of cancer Byproduct of drinking water disinfection
Chlorite
0.8
1.0
Anemia; infants & young children: nervous system effects Byproduct of drinking water disinfection
Haloacetic acids (HAA5)
n/a6
0.0607
Increased risk of cancer Byproduct of drinking water disinfection
Total Trihalomethanes (TTHMs)
<!– none7

–>n/a6

0.0807
Liver, kidney or central nervous system problems; increased risk of cancer Byproduct of drinking water disinfection

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Inorganic Chemicals
Contaminant MCLG1
(mg/L)2
MCL or TT1
(mg/L)2
Potential Health Effects from Ingestion of Water Sources of Contaminant in Drinking Water
Antimony
0.006
0.006
Increase in blood cholesterol; decrease in blood sugar Discharge from petroleum refineries; fire retardants; ceramics; electronics; solder
Arsenic
07
0.010
as of 01/23/06
Skin damage or problems with circulatory systems, and may have increased risk of getting cancer Erosion of natural deposits; runoff from orchards, runoff from glass & electronicsproduction wastes
Asbestos
(fiber >10 micrometers)
7 million fibers per liter
7 MFL
Increased risk of developing benign intestinal polyps Decay of asbestos cement in water mains; erosion of natural deposits
Barium
2
2
Increase in blood pressure Discharge of drilling wastes; discharge from metal refineries; erosion of natural deposits
Beryllium
0.004
0.004
Intestinal lesions Discharge from metal refineries and coal-burning factories; discharge from electrical, aerospace, and defense industries
Cadmium
0.005
0.005
Kidney damage Corrosion of galvanized pipes; erosion of natural deposits; discharge from metal refineries; runoff from waste batteries and paints
Chromium (total)
0.1
0.1
Allergic dermatitis Discharge from steel and pulp mills; erosion of natural deposits
Copper
1.3
TT8;
Action Level=1.3
Short term exposure: Gastrointestinal distressLong term exposure: Liver or kidney damage

People with Wilson’s Disease should consult their personal doctor if the amount of copper in their water exceeds the action level

Corrosion of household plumbing systems; erosion of natural deposits
Cyanide (as free cyanide)
0.2
0.2
Nerve damage or thyroid problems Discharge from steel/metal factories; discharge from plastic and fertilizer factories
Fluoride
4.0
4.0
Bone disease (pain and tenderness of the bones); Children may get mottled teeth Water additive which promotes strong teeth; erosion of natural deposits; discharge from fertilizer and aluminum factories
Lead
zero
TT8;
Action Level=0.015
Infants and children: Delays in physical or mental development; children could show slight deficits in attention span and learning abilitiesAdults: Kidney problems; high blood pressure Corrosion of household plumbing systems; erosion of natural deposits
Mercury (inorganic)
0.002
0.002
Kidney damage Erosion of natural deposits; discharge from refineries and factories; runoff from landfills and croplands
Nitrate (measured as Nitrogen)
10
10
Infants below the age of six months who drink water containing nitrate in excess of the MCL could become seriously ill and, if untreated, may die. Symptoms include shortness of breath and blue-baby syndrome. Runoff from fertilizer use; leaching from septic tanks, sewage; erosion of natural deposits
Nitrite (measured as Nitrogen)
1
1
Infants below the age of six months who drink water containing nitrite in excess of the MCL could become seriously ill and, if untreated, may die. Symptoms include shortness of breath and blue-baby syndrome. Runoff from fertilizer use; leaching from septic tanks, sewage; erosion of natural deposits
Selenium
0.05
0.05
Hair or fingernail loss; numbness in fingers or toes; circulatory problems Discharge from petroleum refineries; erosion of natural deposits; discharge from mines
Thallium
0.0005
0.002
Hair loss; changes in blood; kidney, intestine, or liver problems Leaching from ore-processing sites; discharge from electronics, glass, and drug factories
Organic Chemicals
Contaminant MCLG1
(mg/L)2
MCL or TT1
(mg/L)2
Potential Health Effects from Ingestion of Water
Sources of Contaminant in Drinking Water
Acrylamide
zero
TT9

Nervous system or blood problems; increased risk of cancer

Added to water during sewage/wastewater treatment
Alachlor
zero
0.002

Eye, liver, kidney or spleen problems; anemia; increased risk of cancer

Runoff from herbicide used on row crops
Atrazine
0.003
0.003

Cardiovascular system or reproductive problems

Runoff from herbicide used on row crops
Benzene
zero
0.005

Anemia; decrease in blood platelets; increased risk of cancer

Discharge from factories; leaching from gas storage tanks and landfills
Benzo(a)pyrene (PAHs)
zero
0.0002

Reproductive difficulties; increased risk of cancer

Leaching from linings of water storage tanks and distribution lines
Carbofuran
0.04
0.04

Problems with blood, nervous system, or reproductive system

Leaching of soil fumigant used on rice and alfalfa
Carbon
tetrachloride
zero
0.005

Liver problems; increased risk of cancer

Discharge from chemical plants and other industrial activities
Chlordane
zero
0.002

Liver or nervous system problems; increased risk of cancer

Residue of banned termiticide
Chlorobenzene
0.1
0.1

Liver or kidney problems

Discharge from chemical and agricultural chemical factories
2,4-D
0.07
0.07

Kidney, liver, or adrenal gland problems

Runoff from herbicide used on row crops
Dalapon
0.2
0.2

Minor kidney changes

Runoff from herbicide used on rights of way
1,2-Dibromo-3-chloropropane (DBCP)
zero
0.0002

Reproductive difficulties; increased risk of cancer

Runoff/leaching from soil fumigant used on soybeans, cotton, pineapples, and orchards
o-Dichlorobenzene
0.6
0.6

Liver, kidney, or circulatory system problems

Discharge from industrial chemical factories
p-Dichlorobenzene
0.075
0.075

Anemia; liver, kidney or spleen damage; changes in blood

Discharge from industrial chemical factories
1,2-Dichloroethane
zero
0.005

Increased risk of cancer

Discharge from industrial chemical factories
1,1-Dichloroethylene
0.007
0.007

Liver problems

Discharge from industrial chemical factories
cis-1,2-Dichloroethylene
0.07
0.07

Liver problems

Discharge from industrial chemical factories
trans-1,2-Dichloroethylene
0.1
0.1

Liver problems

Discharge from industrial chemical factories
Dichloromethane
zero
0.005

Liver problems; increased risk of cancer

Discharge from drug and chemical factories
1,2-Dichloropropane
zero
0.005

Increased risk of cancer

Discharge from industrial chemical factories
Di(2-ethylhexyl) adipate
0.4
0.4

Weight loss, liver problems, or possible reproductive difficulties.

Discharge from chemical factories
Di(2-ethylhexyl) phthalate
zero
0.006

Reproductive difficulties; liver problems; increased risk of cancer

Discharge from rubber and chemical factories
Dinoseb
0.007
0.007

Reproductive difficulties

Runoff from herbicide used on soybeans and vegetables
Dioxin (2,3,7,8-TCDD)
zero
0.00000003

Reproductive difficulties; increased risk of cancer

Emissions from waste incineration and other combustion; discharge from chemical factories
Diquat
0.02
0.02

Cataracts

Runoff from herbicide use
Endothall
0.1
0.1

Stomach and intestinal problems

Runoff from herbicide use
Endrin
0.002
0.002

Liver problems

Residue of banned insecticide
Epichlorohydrin
zero
TT9

Increased cancer risk, and over a long period of time, stomach problems

Discharge from industrial chemical factories; an impurity of some water treatment chemicals
Ethylbenzene
0.7
0.7

Liver or kidneys problems

Discharge from petroleum refineries
Ethylene dibromide
zero
0.00005

Problems with liver, stomach, reproductive system, or kidneys; increased risk of cancer

Discharge from petroleum refineries
Glyphosate
0.7
0.7

Kidney problems; reproductive difficulties

Runoff from herbicide use
Heptachlor
zero
0.0004

Liver damage; increased risk of cancer

Residue of banned termiticide
Heptachlor epoxide
zero
0.0002

Liver damage; increased risk of cancer

Breakdown of heptachlor
Hexachlorobenzene
zero
0.001

Liver or kidney problems; reproductive difficulties; increased risk of cancer

Discharge from metal refineries and agricultural chemical factories
Hexachlorocyclopentadiene
0.05
0.05

Kidney or stomach problems

Discharge from chemical factories
Lindane
0.0002
0.0002

Liver or kidney problems

Runoff/leaching from insecticide used on cattle, lumber, gardens
Methoxychlor
0.04
0.04

Reproductive difficulties

Runoff/leaching from insecticide used on fruits, vegetables, alfalfa, livestock
Oxamyl (Vydate)
0.2
0.2

Slight nervous system effects

Runoff/leaching from insecticide used on apples, potatoes, and tomatoes
Polychlorinated
biphenyls (PCBs)
zero
0.0005

Skin changes; thymus gland problems; immune deficiencies; reproductive or nervous system difficulties; increased risk of cancer

Runoff from landfills; discharge of waste chemicals
Pentachlorophenol
zero
0.001

Liver or kidney problems; increased cancer risk

Discharge from wood preserving factories
Picloram
0.5
0.5

Liver problems

Herbicide runoff
Simazine
0.004
0.004

Problems with blood

Herbicide runoff
Styrene
0.1
0.1

Liver, kidney, or circulatory system problems

Discharge from rubber and plastic factories; leaching from landfills
Tetrachloroethylene
zero
0.005

Liver problems; increased risk of cancer

Discharge from factories and dry cleaners
Toluene
1
1

Nervous system, kidney, or liver problems

Discharge from petroleum factories
Toxaphene
zero
0.003

Kidney, liver, or thyroid problems; increased risk of cancer

Runoff/leaching from insecticide used on cotton and cattle
2,4,5-TP (Silvex)
0.05
0.05

Liver problems

Residue of banned herbicide
1,2,4-Trichlorobenzene
0.07
0.07

Changes in adrenal glands

Discharge from textile finishing factories
1,1,1-Trichloroethane
0.20
0.2

Liver, nervous system, or circulatory problems

Discharge from metal degreasing sites and other factories
1,1,2-Trichloroethane
0.003
0.005

Liver, kidney, or immune system problems

Discharge from industrial chemical factories
Trichloroethylene
zero
0.005

Liver problems; increased risk of cancer

Discharge from metal degreasing sites and other factories
Vinyl chloride
zero
0.002

Increased risk of cancer

Leaching from PVC pipes; discharge from plastic factories
Xylenes (total)
10
10

Nervous system damage

Discharge from petroleum factories; discharge from chemical factories

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Radionuclides
Contaminant MCLG1
(mg/L)2
MCL or TT1
(mg/L)2
Potential Health Effects from Ingestion of Water Sources of Contaminant in Drinking Water
Alpha particles
none7
———-
zero
15 picocuries per Liter (pCi/L)
Increased risk of cancer Erosion of natural deposits of certain minerals that are radioactive and may emit a form of radiation known as alpha radiation
Beta particles and photon emitters
none7
———-
zero
4 millirems per year
Increased risk of cancer Decay of natural and man-made deposits ofcertain minerals that are radioactive and may emit forms of radiation known as photons and beta radiation
Radium 226 and Radium 228 (combined)
none7
———-
zero
5 pCi/L
Increased risk of cancer Erosion of natural deposits
Uranium
zero

30 ug/L
as of 12/08/03

Increased risk of cancer, kidney toxicity Erosion of natural deposits

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Notes From EPA WEB PAGE: http://www.epa.gov/safewater/contaminants/index.html#mcls

1 Definitions:
Maximum Contaminant Level (MCL) – The highest level of a contaminant that is allowed in drinking water. MCLs are set as close to MCLGs as feasible using the best available treatment technology and taking cost into consideration. MCLs are enforceable standards.
Maximum Contaminant Level Goal (MCLG) – The level of a contaminant in drinking water below which there is no known or expected risk to health. MCLGs allow for a margin of safety and are non-enforceable public health goals.
Maximum Residual Disinfectant Level (MRDL) – The highest level of a disinfectant allowed in drinking water. There is convincing evidence that addition of a disinfectant is necessary for control of microbial contaminants.
Maximum Residual Disinfectant Level Goal (MRDLG) – The level of a drinking water disinfectant below which there is no known or expected risk to health. MRDLGs do not reflect the benefits of the use of disinfectants to control microbial contaminants.
Treatment Technique – A required process intended to reduce the level of a contaminant in drinking water.

2 Units are in milligrams per liter (mg/L) unless otherwise noted. Milligrams per liter are equivalent to parts per million.

3 EPA’s surface water treatment rules require systems using surface water or ground water under the direct influence of surface water to (1) disinfect their water, and (2) filter their water or meet criteria for avoiding filtration so that the following contaminants are controlled at the following levels:

  • Cryptosporidium: (as of1/1/02 for systems serving >10,000 and 1/14/05 for systems serving <10,000) 99% removal.
  • Giardia lamblia: 99.9% removal/inactivation
  • Viruses: 99.99% removal/inactivation
  • Legionella: No limit, but EPA believes that if Giardia and viruses are removed/inactivated, Legionella will also be controlled.
  • Turbidity: At no time can turbidity (cloudiness of water) go above 5 nephelolometric turbidity units (NTU); systems that filter must ensure that the turbidity go no higher than 1 NTU (0.5 NTU for conventional or direct filtration) in at least 95% of the daily samples in any month. As of January 1, 2002, turbidity may never exceed 1 NTU, and must not exceed 0.3 NTU in 95% of daily samples in any month.
  • HPC: No more than 500 bacterial colonies per milliliter.
  • Long Term 1 Enhanced Surface Water Treatment (Effective Date: January 14, 2005); Surface water systems or (GWUDI) systems serving fewer than 10,000 people must comply with the applicable Long Term 1 Enhanced Surface Water Treatment Rule provisions (e.g. turbidity standards, individual filter monitoring, Cryptosporidium removal requirements, updated watershed control requirements for unfiltered systems).
  • Long Term 2 Enhanced Surface Water Treatment Rule (Effective Date: January 4, 2006) – Surface water systems or GWUDI systems must comply with the additional treatment for Cryptosporidium specified in this rule based on their Cryptosporidium bin classification calculated after the completion of source water monitoring.
  • Filter Backwash Recycling; The Filter Backwash Recycling Rule requires systems that recycle to return specific recycle flows through all processes of the system’s existing conventional or direct filtration system or at an alternate location approved by the state.

4 more than 5.0% samples total coliform-positive in a month. (For water systems that collect fewer than 40 routine samples per month, no more than one sample can be total coliform-positive per month.) Every sample that has total coliform must be analyzed for either fecal coliforms or E. coli if two consecutive TC-positive samples, and one is also positive for E.coli fecal coliforms, system has an acute MCL violation.

5 Fecal coliform and E. coli are bacteria whose presence indicates that the water may be contaminated with human or animal wastes. Disease-causing microbes (pathogens) in these wastes can cause diarrhea, cramps, nausea, headaches, or other symptoms. These pathogens may pose a special health risk for infants, young children, and people with severely compromised immune systems.

6 Although there is no collective MCLG for this contaminant group, there are individual MCLGs for some of the individual contaminants:

  • Trihalomethanes: bromodichloromethane (zero); bromoform (zero); dibromochloromethane (0.06 mg/L): chloroform (0.07mg/L).
  • Haloacetic acids: dichloroacetic acid (zero); trichloroacetic acid (0.02 mg/L); monochloroacetic acid (0.07 mg/L). Bromoacetic acid and dibromoacetic acid are regulated with this group but have no MCLGs.

7 The MCL values are the same in the Stage 2 DBPR as they were in the Stage 1 DBPR, but compliance with the MCL is based on different calculations. Under Stage 1, compliance is based on a running annual average (RAA). Under Stage 2, compliance is based on a locational running annual average (LRAA), where the annual average at each sampling location in the distribution system is used to determine compliance with the MCLs. The LRAA requirement will become effective April 1, 2012 for systems on schedule 1, October 1, 2012 for systems on schedule 2, and October 1, 2013 for all remaining systems.

8 Lead and copper are regulated by a Treatment Technique that requires systems to control the corrosiveness of their water. If more than 10% of tap water samples exceed the action level, water systems must take additional steps. For copper, the action level is 1.3 mg/L, and for lead is 0.015 mg/L.

9 Each water system must certify, in writing, to the state (using third-party or manufacturer’s certification) that when acrylamide and epichlorohydrin are used in drinking water systems, the combination (or product) of dose and monomer level does not exceed the levels specified, as follows:

  • Acrylamide = 0.05% dosed at 1 mg/L (or equivalent)
  • Epichlorohydrin = 0.01% dosed at 20 mg/L (or equivalent)

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National Secondary Drinking Water Regulations

National Secondary Drinking Water Regulations (NSDWRs or secondary standards) are non-enforceable guidelines regulating contaminants that may cause cosmetic effects (such as skin or tooth discoloration) or aesthetic effects (such as taste, odor, or color) in drinking water. EPA recommends secondary standards to water systems but does not require systems to comply. However, states may choose to adopt them as enforceable standards.

List of National Secondary Drinking Water Regulations
Contaminant
Secondary Standard
Aluminum
0.05 to 0.2 mg/L
Chloride
250 mg/L
Color
15 (color units)
Copper
1.0 mg/L
Corrosivity
noncorrosive
Fluoride
2.0 mg/L
Foaming Agents
0.5 mg/L
Iron
0.3 mg/L
Manganese
0.05 mg/L
Odor
3 threshold odor number
pH
6.5-8.5
Silver
0.10 mg/L
Sulfate
250 mg/L
Total Dissolved Solids
500 mg/L
Zinc
5 mg/L


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Unregulated Contaminants

This list of contaminants which, at the time of publication, are not subject to any proposed or promulgated national primary drinking water regulation (NPDWR), are known or anticipated to occur in public water systems, and may require regulations under SDWA. For more information check out the list, or vist the Drinking Water Contaminant Candidate List (CCL) web site.

—————–

This page has been republished on this site to make it easier to find the list of Drinking Water Contaminants.

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